Government is about making tough choices: ruling over, rather than being ruled by, vested interests. One Nation Labour's objective is to require all to behave responsibly, including those at the top. And it's about governing for the many, not the few. While other parties hesitated, Ed Miliband spoke for the country, when evidence of phone hacking within the Murdoch empire emerged. By contrast, the Tory-led government is weak in the face of the powerful few. It has made the wrong choices; while millions are hit by a cost-of-living crisis, they gave a tax cut to millionaires.

In order to regain confidence in the political system, we will need to make the correct call in relation to the influence of big money in politics. This is why Miliband called for a cap on donations to political parties. He suggested a cap of £5,000 per donor. This would be painful for all parties, including Labour, but it is right to tackle the problem. Lobbying is a necessary part of our democracy. Unlike elsewhere, the lobbying industry in Britain is not subject to regulatory requirements.

Now the government has published a lobbying bill. It is weak, ambiguous and lacking in transparency. Last week, I met with senior representatives of the lobbying industry and campaigners. Not one of them was able to say that the legislation would mean they would have to register. Instead of introducing transparency, the bill has created uncertainty. In fact, the government's proposed register covers only so-called "consultant lobbyists" who lobby ministers and the most senior civil servants. It will not include those who lobby special advisers, MPs or mid-ranking civil servants, therefore leaving more than four-fifths of lobbyists outside the remit of the register.

In truth, the bill is a cynical attempt to deceive the public into believing they are regulating lobbying while in fact they have done no such thing. As a consequence, the bill would not have covered most of the lobbying scandals that have so frequently engulfed the Tory party.

It will not catch Lynton Crosby, whose clients include big tobacco companies, fracking organisations and private healthcare firms. Without transparency the perception will always arise in the public's mind of big money influence in No 10 on policies, where powerful commercial interests are at stake.

Beyond lobbying, there are other matters that need to be addressed if we are to remove the impression that politics is being damaged by the influence of commercial interests. Labour will tackle the issue of MPs' second jobs where the Tories have shown their true colours in the recent Commons debate. They defended their paid directorships and consultancies and the large salaries that accompanied them, which is not surprising, seeing as almost one in three Tory MPs have a second job from which last year they collectively earned £4.5m.

We will seek to regulate the so-called "revolving door", by which individuals are able to move too easily between positions of influence in government into the private sector without proper protections being put in place. Through an amendment to the lobbying bill, we will seek to ensure there is proper oversight of conflicts of interests when people take up senior roles in government, only to leave and then immediately take their expertise, knowledge and insights into the commercial sector.

There is a widespread sense of alienation from politics. In part, this stems from a feeling that Britain is governed by a closed circle at the top, which excludes the millions of hard-working people who play by the rules but who are struggling to get by. On the questions of lobbying regulation, MPs' second jobs and revolving door appointments, urgent reform is required. But Cameron and his colleagues have proved time and time again that they stand up for the wrong people.

We have a government in the grip of vested interests rather than one that is strong enough to take a grip. This is why we need radical changes in the way we are governed. These are changes that Labour is determined to press ahead with. Labour will introduce amendments to the lobbying bill that tackle the vested interests that have tarnished the reputation of politics.

• This article was amended on 21 August 2013. The original stated that David Cameron approved the appointment of Dave Hartnett "without appearing to have referred the case in the first instance to the advisory committee on business appointments". This has been corrected.